Generator brush grinder



April 1938 c. G. MULLER. 2,112,994

GENERATOR BRUSH GRINDER Filed May 14, 1937 Inventor C. Mu/Zfer ,4 itorneys Patented Apr. 5, 1938 UNITED STATES PATENT OFFICE 1 Claim.

This invention relates to a grinder device for brushes of generators, the general object of the invention being to provide a band of resilient material and having an abrasive outer face so that when the band is placed on the commutator with the brushes engaging the abrasive face and the parts rocked, said abrasive face will grind or cut the ends of the brushes whereby said brushes will properly contact the commutator when the band is removed and the generator is in operation.

This invention also consists in certain other features of construction and in the combination and arrangement of several parts, to be hereinafter fully described, illustrated in the accompanying drawing and specifically pointed out in the appended claim.

In describing the invention in detail, reference will be had to the accompanying drawing wherein like characters denote like or corresponding parts throughout the several views, and in which:

Figure l is an end view showing the invention in use, the parts of the generator being shown in dotted lines.

Figure 2 is a top plan view of the device.

Figure 3 is an end View.

Figure 4 is a section on the line 44 of Figure 3.

In this drawing the numeral 1 indicates the band or ring formed of thin spring metal or the like and of split construction. The outer face or circumference of the band or ring is roughened as shown at 2 to form a cutting or abrading face. Instead of roughening the outer circumference sand paper or the like may be suitably attached to said face. Lugs 3 are formed on the inner circumference of the band for engaging the notches in the commutator, shown in Figure 1,

so as to prevent the ring or band slipping on the commutator.

The device is expansib-le due to its spring construction and can be placed on commutators of different sizes.

It will, of course, be understood that the generator must be disassembled sufficiently topermit the device to be put in place with the brushes engaging the outer circumference thereof as shown in dotted lines in Figure 1. Then the parts are rocked to cause the abrasive face of the band to engage the ends of the brushes. The brushes are quickly serviced by the device in a uniform manner and after the brushes have been ground to the proper contour the armature is slipped out of the brush end from the generator, the grinder removed and the generator reassembled.

It is thought from the foregoing description that the advantages and novel features of the invention will be readily apparent.

It is to be understood that changes may be made in the construction and in the combine tion and arrangement of the several parts, provided that such changes fall within the scope of the appended claim.

What is claimed is:-

A grinding device for the brushes of a generator which includes a commutator having spaced notches therein, comprising a split ring of spring -metal adapted to fit over the commutator, transversely extending lugs on the inner circumference of the ring and spaced apart substantially the same distances as the notches are spaced apart, said lugs engaging the notches and said ring having an abrasive outer circumference.

CHRISTIAN G. MULLER. 

